[PATCH v2] x86/therm_throt.c: Fix error handling in thermal_throttle_add_dev

[Fenghua Yu]

From: Fenghua Yu <fenghua.yu@xxxxxxxxx>

When sysfs_add_file_to_group fails, thermal_throttle_add_dev removes the
created group and returns with the error code and the driver cleans up and
returns with the error code. Thus the driver either installs all devices
successfully or doesn't install any device at all.

Signed-off-by: Fenghua Yu <fenghua.yu@xxxxxxxxx>
---
 arch/x86/kernel/cpu/mcheck/therm_throt.c |   36 ++++++++++++++++++++++++++---
 1 files changed, 32 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/cpu/mcheck/therm_throt.c b/arch/x86/kernel/cpu/mcheck/therm_throt.c
index c2a8b26..5099e90 100644
--- a/arch/x86/kernel/cpu/mcheck/therm_throt.c
+++ b/arch/x86/kernel/cpu/mcheck/therm_throt.c
@@ -211,19 +211,33 @@ static __cpuinit int thermal_throttle_add_dev(struct sys_device *sys_dev)
 	if (err)
 		return err;
 
-	if (cpu_has(c, X86_FEATURE_PLN))
+	if (cpu_has(c, X86_FEATURE_PLN)) {
 		err = sysfs_add_file_to_group(&sys_dev->kobj,
 					      &attr_core_power_limit_count.attr,
 					      thermal_attr_group.name);
-	if (cpu_has(c, X86_FEATURE_PTS))
+		if (err)
+			goto error;
+	}
+
+	if (cpu_has(c, X86_FEATURE_PTS)) {
 		err = sysfs_add_file_to_group(&sys_dev->kobj,
 					      &attr_package_throttle_count.attr,
 					      thermal_attr_group.name);
-		if (cpu_has(c, X86_FEATURE_PLN))
+		if (err)
+			goto error;
+
+		if (cpu_has(c, X86_FEATURE_PLN)) {
 			err = sysfs_add_file_to_group(&sys_dev->kobj,
 					&attr_package_power_limit_count.attr,
 					thermal_attr_group.name);
+			if (err)
+				goto error;
+		}
+	}
 
+	return 0;
+error:
+	sysfs_remove_group(&sys_dev->kobj, &thermal_attr_group);
 	return err;
 }
 
@@ -275,6 +289,7 @@ static struct notifier_block thermal_throttle_cpu_notifier __cpuinitdata =
 static __init int thermal_throttle_init_device(void)
 {
 	unsigned int cpu = 0;
+	int i;
 	int err;
 
 	if (!atomic_read(&therm_throt_en))
@@ -288,13 +303,26 @@ static __init int thermal_throttle_init_device(void)
 	/* connect live CPUs to sysfs */
 	for_each_online_cpu(cpu) {
 		err = thermal_throttle_add_dev(get_cpu_sysdev(cpu));
-		WARN_ON(err);
+		if (err)
+			goto error;
 	}
 #ifdef CONFIG_HOTPLUG_CPU
 	mutex_unlock(&therm_cpu_lock);
 #endif
 
 	return 0;
+error:
+	WARN_ON(err);
+
+	/* cleanup. */
+	for (i = 0; i < cpu; i++)
+		thermal_throttle_remove_dev(get_cpu_sysdev(i));
+#ifdef CONFIG_HOTPLUG_CPU
+	mutex_unlock(&therm_cpu_lock);
+#endif
+	unregister_hotcpu_notifier(&thermal_throttle_cpu_notifier);
+
+	return err;
 }
 device_initcall(thermal_throttle_init_device);
 
-- 
1.6.0.3

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